RTK Rover & Base - What’s The Difference Between RTK & DGPS?

Relevant part starts at 2:00

[@marquisdemoo1792]

Husqvarna has a Robotic Mower using a fixed Reference Point with an antenna, which they call EPOS. To cover my lawns I would potentially put the Reference Point on top of my tall building, but given the building is 13th Century it has very thick walls so mowing up to the building edge the mower would probably go into shadow. Husqvarna simplistically state that if the reference signal is lost the mower stops and their system is only designed for wide open spaces. I wondered if the actual position of the antenna for the Reference Point was critical, in other words is the actual signal to the Reference Point used to determine location, or is it just transmitting GPS correction data. If the former then multiple Reference Points would be required, but if the latter then it is simply a matter of adding antenna diversity to cover the dead spots.

[@Inertialsense]

Great observations and questions! You are most likely right about the 13th century walls causing issues with the GNSS. However, rather than having multiple reference points, you really only need one good one (like on the top of your building, like you said). Any shadows that would hinder the radio signal from the base station (RTK) to the mower would be solved by simply adding a repeater (not reference point). Other than that, adding additional and potentially higher quality sensors to the mower would be more environmentally robust. For instance, your mower and base station will likely experience multi-pathing errors from the signal bouncing off all the objects there. Adding a multi-band sensor that samples extra frequencies would help eliminate those errors. In short, for your particular situation, RTK with Multi-Band INS sensors, would do the trick, even if it's right directly below the reference point. But the real meat would be getting visual and LiDAR on the mower. (Warning: Here comes the plug). We are currently developing such a system that would be retrofitted onto commercial mowers that would have awesome GNSS sensors, combined with vision, LiDAR, wheel odometry, etc to give the mower access to "GPS Denied" areas to complete its mission.

[@marquisdemoo1792]

@@Inertialsense Many thanks. I think Ambrogio have LiDAR on their mowers but that is just collision avoidance. They also do a small mower that senses when it is off grass or crossing a curb, which does not need a boundary wire, but it doesn't know where it is and doesn't have a base station. So far the only semi-domestic non boundary wire self charging solution is Husqvarna's EPOS, unless there is something in China, so I will await your 'plugged' system with interest! I'm pretty sure AI with the appropriate sensors is the way ahead.

[@luftstolle]

Yeah... You're not explaining the difference, you're just saying "it's newer".

[@luisfernandotorresramon1340]

Yes I agre, I was asking a friend and them said the way of correction, for example RTK works with Radio en Mhz and need the whipy antena and for GPPS system you have onlye correcion of satalites throuth Antena in an specific area covering interested area. Sorry for my bad english sir. and have a good day.